Method of making magnetic materials.



UNITED STAT E PATENT oFFIoE. snoenRTiA. HADFI'EL'D, 01% SHEFFIELD, ENGLAND.

METHOD OF MAKINGIMAGNETICI MATERIALS- Specification of Letters Patent.

Patented Nov. 27, 1906. A

Application filed July 5. 1906. Serial No. 324.898.

To all whom/t t may concern.-

have described and claimed a method of making magnetic material which consists in roll? ing an alloy of iron combined with other ele- I ments, more particularly silicon, aluminium,

or phosphorus, into thin sheets and then subjecting said rolled sheets to a heat treatment of two ste s. As the magnetic material referred -to 1s cold-short the rolling or for ing of the alloy into thin sheets, as set fort in mec anically treated.

my patent aforesaid, necessarily implies a preliminary heating of said alloy to a high tern erature in order to enable it to be thus Hence the said alloy is really treated three times-th at is to say,

once before mechanical treatment and twice afterward. I

In carrying my present process into effect I eliminate one of these subsequent heat treatments, or, rather,substitute for it the preliminary heating before mechanical treatment, and this I have broadly claimed in another application for Letters Patent, Serial No. 324,896, filed July 5, 1.906. My present invention is a specific-form of said process, and in practicing the same I first heat the material to between 900 and 1,000 centigrade, then roll it or otherwise mechanically reduce it to a thin sheet, then reheat to between 700 and 800centigrade, and finally cool.

The method of producing a magnetic material of high permeability and lowhysteresis action, which consists'in alloying a magnetic substance with silicon, heating said substance to a temperature below its melting '-point, mechanically treatin said. substance to reduce it to a sheet, re eating said sheet to a temperature below its melting-point and below said first-named temperature, and finally cooling.

In witness whereof .I have signed my name hereto int-he presence of two witnesses.

ROBERT A. AD'FIELD.

, Witnesses: I

, HENRY E. DIXON,

FRANK HUTSON. 

